From dec94e70e12c39440e63159e0050d46795dfcf09 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Mon, 24 Sep 2012 11:13:15 +0100
Subject: [PATCH 01/21] SERIAL: core: use local variable uport in
 uart_set_termios()

This is to make the following change more clear.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/serial_core.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 0fcfd98a9566..bc2065d323b9 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1210,6 +1210,7 @@ static void uart_set_termios(struct tty_struct *tty,
 						struct ktermios *old_termios)
 {
 	struct uart_state *state = tty->driver_data;
+	struct uart_port *uport = state->uart_port;
 	unsigned long flags;
 	unsigned int cflag = tty->termios.c_cflag;
 
@@ -1232,31 +1233,31 @@ static void uart_set_termios(struct tty_struct *tty,
 
 	/* Handle transition to B0 status */
 	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
-		uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
+		uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
 	/* Handle transition away from B0 status */
 	else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
 		unsigned int mask = TIOCM_DTR;
 		if (!(cflag & CRTSCTS) ||
 		    !test_bit(TTY_THROTTLED, &tty->flags))
 			mask |= TIOCM_RTS;
-		uart_set_mctrl(state->uart_port, mask);
+		uart_set_mctrl(uport, mask);
 	}
 
 	/* Handle turning off CRTSCTS */
 	if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
-		spin_lock_irqsave(&state->uart_port->lock, flags);
+		spin_lock_irqsave(&uport->lock, flags);
 		tty->hw_stopped = 0;
 		__uart_start(tty);
-		spin_unlock_irqrestore(&state->uart_port->lock, flags);
+		spin_unlock_irqrestore(&uport->lock, flags);
 	}
 	/* Handle turning on CRTSCTS */
 	else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
-		spin_lock_irqsave(&state->uart_port->lock, flags);
-		if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
+		spin_lock_irqsave(&uport->lock, flags);
+		if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
 			tty->hw_stopped = 1;
-			state->uart_port->ops->stop_tx(state->uart_port);
+			uport->ops->stop_tx(uport);
 		}
-		spin_unlock_irqrestore(&state->uart_port->lock, flags);
+		spin_unlock_irqrestore(&uport->lock, flags);
 	}
 }
 

From 2cbacafd7af0f1cc7a433668c662a91ba6aabc1b Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Tue, 17 Apr 2012 16:34:13 +0100
Subject: [PATCH 02/21] SERIAL: core: add hardware assisted s/w flow control
 support

Ports which are capable of handling s/w flow control in hardware to
know when the s/w flow control termios settings are changed.  Add a
flag to allow the low level serial drivers to indicate that they
support this, and these changes should be propagated to them.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/serial_core.c | 16 ++++++++++++++--
 include/linux/serial_core.h      |  2 ++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index bc2065d323b9..bd10bbd56446 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1213,7 +1213,19 @@ static void uart_set_termios(struct tty_struct *tty,
 	struct uart_port *uport = state->uart_port;
 	unsigned long flags;
 	unsigned int cflag = tty->termios.c_cflag;
+	unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
+	bool sw_changed = false;
 
+	/*
+	 * Drivers doing software flow control also need to know
+	 * about changes to these input settings.
+	 */
+	if (uport->flags & UPF_SOFT_FLOW) {
+		iflag_mask |= IXANY|IXON|IXOFF;
+		sw_changed =
+		   tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
+		   tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
+	}
 
 	/*
 	 * These are the bits that are used to setup various
@@ -1221,11 +1233,11 @@ static void uart_set_termios(struct tty_struct *tty,
 	 * bits in c_cflag; c_[io]speed will always be set
 	 * appropriately by set_termios() in tty_ioctl.c
 	 */
-#define RELEVANT_IFLAG(iflag)	((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
 	if ((cflag ^ old_termios->c_cflag) == 0 &&
 	    tty->termios.c_ospeed == old_termios->c_ospeed &&
 	    tty->termios.c_ispeed == old_termios->c_ispeed &&
-	    RELEVANT_IFLAG(tty->termios.c_iflag ^ old_termios->c_iflag) == 0) {
+	    ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
+	    !sw_changed) {
 		return;
 	}
 
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 3c430228d232..00051388de3c 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -163,6 +163,8 @@ struct uart_port {
 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
 #define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
+/* Port has hardware-assisted s/w flow control */
+#define UPF_SOFT_FLOW		((__force upf_t) (1 << 22))
 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
 #define UPF_EXAR_EFR		((__force upf_t) (1 << 25))

From dba05832cbe4f305dfd998fb26d7c685d91fbbd8 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Tue, 17 Apr 2012 16:41:10 +0100
Subject: [PATCH 03/21] SERIAL: core: add hardware assisted h/w flow control
 support

Ports which are handling h/w flow control in hardware must not have
their RTS state altered depending on the tty's hardware-stopped state.
Avoid this additional logic when setting the termios state.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/serial_core.c | 7 +++++++
 include/linux/serial_core.h      | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index bd10bbd56446..9d8796e77188 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1255,6 +1255,13 @@ static void uart_set_termios(struct tty_struct *tty,
 		uart_set_mctrl(uport, mask);
 	}
 
+	/*
+	 * If the port is doing h/w assisted flow control, do nothing.
+	 * We assume that tty->hw_stopped has never been set.
+	 */
+	if (uport->flags & UPF_HARD_FLOW)
+		return;
+
 	/* Handle turning off CRTSCTS */
 	if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
 		spin_lock_irqsave(&uport->lock, flags);
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 00051388de3c..e2cda5d04e48 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -163,6 +163,8 @@ struct uart_port {
 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
 #define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
+/* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
+#define UPF_HARD_FLOW		((__force upf_t) (1 << 21))
 /* Port has hardware-assisted s/w flow control */
 #define UPF_SOFT_FLOW		((__force upf_t) (1 << 22))
 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))

From 9aba8d5b011193c8e01d565c5b585df5b94f1db2 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Tue, 17 Apr 2012 17:23:14 +0100
Subject: [PATCH 04/21] SERIAL: core: add throttle/unthrottle callbacks for
 hardware assisted flow control

Add two callbacks for hardware assisted flow control; we need to know
when the tty layers want us to stop and restart due to their buffer
levels.

Call a driver specific throttle/unthrottle function if and only if the
driver indicates that it is using an enabled hardware assisted flow
control method, otherwise fall back to the non-hardware assisted
methods.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/serial_core.c | 31 +++++++++++++++++++++++++++----
 include/linux/serial_core.h      |  2 ++
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 9d8796e77188..098bb99c2b9f 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -610,27 +610,50 @@ static void uart_send_xchar(struct tty_struct *tty, char ch)
 static void uart_throttle(struct tty_struct *tty)
 {
 	struct uart_state *state = tty->driver_data;
+	struct uart_port *port = state->uart_port;
+	uint32_t mask = 0;
 
 	if (I_IXOFF(tty))
+		mask |= UPF_SOFT_FLOW;
+	if (tty->termios.c_cflag & CRTSCTS)
+		mask |= UPF_HARD_FLOW;
+
+	if (port->flags & mask) {
+		port->ops->throttle(port);
+		mask &= ~port->flags;
+	}
+
+	if (mask & UPF_SOFT_FLOW)
 		uart_send_xchar(tty, STOP_CHAR(tty));
 
-	if (tty->termios.c_cflag & CRTSCTS)
-		uart_clear_mctrl(state->uart_port, TIOCM_RTS);
+	if (mask & UPF_HARD_FLOW)
+		uart_clear_mctrl(port, TIOCM_RTS);
 }
 
 static void uart_unthrottle(struct tty_struct *tty)
 {
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port = state->uart_port;
+	uint32_t mask = 0;
 
-	if (I_IXOFF(tty)) {
+	if (I_IXOFF(tty))
+		mask |= UPF_SOFT_FLOW;
+	if (tty->termios.c_cflag & CRTSCTS)
+		mask |= UPF_HARD_FLOW;
+
+	if (port->flags & mask) {
+		port->ops->unthrottle(port);
+		mask &= ~port->flags;
+	}
+
+	if (mask & UPF_SOFT_FLOW) {
 		if (port->x_char)
 			port->x_char = 0;
 		else
 			uart_send_xchar(tty, START_CHAR(tty));
 	}
 
-	if (tty->termios.c_cflag & CRTSCTS)
+	if (mask & UPF_HARD_FLOW)
 		uart_set_mctrl(port, TIOCM_RTS);
 }
 
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index e2cda5d04e48..c6690a2a27fb 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -46,6 +46,8 @@ struct uart_ops {
 	unsigned int	(*get_mctrl)(struct uart_port *);
 	void		(*stop_tx)(struct uart_port *);
 	void		(*start_tx)(struct uart_port *);
+	void		(*throttle)(struct uart_port *);
+	void		(*unthrottle)(struct uart_port *);
 	void		(*send_xchar)(struct uart_port *, char ch);
 	void		(*stop_rx)(struct uart_port *);
 	void		(*enable_ms)(struct uart_port *);

From 0d5b16639523970db001e6af298e360782f4d89a Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Fri, 5 Oct 2012 23:48:28 +0100
Subject: [PATCH 05/21] SERIAL: omap: allow hardware assisted rts/cts modes to
 be disabled

There is nothing which clears the auto RTS/CTS bits, so once hardware
flow control gets enabled, there's no possibility to disable it.
So, clear these bits when CRTSCTS is cleared.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 6d3d26a607b9..b6a1925dfc92 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -921,6 +921,13 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 		serial_out(up, UART_MCR, up->mcr | UART_MCR_RTS);
 		serial_out(up, UART_LCR, cval);
+	} else {
+		/* Disable AUTORTS and AUTOCTS */
+		up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS);
+
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_out(up, UART_EFR, up->efr);
+		serial_out(up, UART_LCR, cval);
 	}
 
 	serial_omap_set_mctrl(&up->port, up->port.mctrl);

From da5d01f23bc1ff710797a563ca3616df95395a12 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 6 Oct 2012 00:11:16 +0100
Subject: [PATCH 06/21] SERIAL: omap: allow hardware assisted IXANY mode to be
 disabled

Nothing was clearing the UART_MCR_XONANY bit, so once the ixany
mode gets set, there's no possibility to disable it.  Clear this
bit when IXANY mode is cleared.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index b6a1925dfc92..f5b2f395af2d 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -698,6 +698,8 @@ serial_omap_configure_xonxoff
 	 */
 	if (termios->c_iflag & IXANY)
 		up->mcr |= UART_MCR_XONANY;
+	else
+		up->mcr &= ~UART_MCR_XONANY;
 
 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

From d864c03bfce2449703c7f0544dac3fbaed347239 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 6 Oct 2012 00:51:17 +0100
Subject: [PATCH 07/21] SERIAL: omap: remove setting of EFR SCD bit

The SCD (special character detect) bit enables comparisons with XOFF2,
which we do not program.  As the XOFF2 character remains unprogrammed,
there's little point enabling this feature along with its associated
interrupt.  Remove this, and ensure that the SCD bit is cleared.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index f5b2f395af2d..71f968b5504c 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -704,13 +704,8 @@ serial_omap_configure_xonxoff
 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
-	/* Enable special char function UARTi.EFR_REG[5] and
-	 * load the new software flow control mode IXON or IXOFF
-	 * and restore the UARTi.EFR_REG[4] ENHANCED_EN value.
-	 */
-	serial_out(up, UART_EFR, up->efr | UART_EFR_SCD);
+	serial_out(up, UART_EFR, up->efr);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-
 	serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR);
 	serial_out(up, UART_LCR, up->lcr);
 }
@@ -843,6 +838,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 
 	up->efr = serial_in(up, UART_EFR);
+	up->efr &= ~UART_EFR_SCD;
 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
 
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);

From 511e74f3305e9fce1410f2205084fd67c50f81bc Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Fri, 5 Oct 2012 15:13:56 +0100
Subject: [PATCH 08/21] SERIAL: omap: no need to re-read EFR

There's no need to re-read EFR after we've recently written it; the
register is a configuration register which doesn't change its value
without us writing to it.  The last value which was written to this
register was up->efr.

Removing this re-reading avoids the possibility that we end up with
up->efr having unintended bits set, which should only be temporarily
set when accessing the enhanced features.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 71f968b5504c..6ef4cc49d81e 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -873,8 +873,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
 
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-
-	up->efr = serial_in(up, UART_EFR);
 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
 
 	serial_out(up, UART_LCR, 0);

From 9363f8fa8930db6383b4089036799a276257fdb7 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Fri, 5 Oct 2012 12:23:28 +0100
Subject: [PATCH 09/21] SERIAL: omap: fix set_mctrl() breakage

c538d20c7f (and maybe previous commits) broke set_mctrl() by making
it only capable of setting bits in the MCR register.  This prevents
software controlled flow control and modem control line manipulation
via TIOCMSET/TIOCMBIC from working correctly.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 6ef4cc49d81e..fb06def4d982 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -504,7 +504,7 @@ static unsigned int serial_omap_get_mctrl(struct uart_port *port)
 static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	struct uart_omap_port *up = to_uart_omap_port(port);
-	unsigned char mcr = 0;
+	unsigned char mcr = 0, old_mcr;
 
 	dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line);
 	if (mctrl & TIOCM_RTS)
@@ -519,8 +519,10 @@ static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
 		mcr |= UART_MCR_LOOP;
 
 	pm_runtime_get_sync(up->dev);
-	up->mcr = serial_in(up, UART_MCR);
-	up->mcr |= mcr;
+	old_mcr = serial_in(up, UART_MCR);
+	old_mcr &= ~(UART_MCR_LOOP | UART_MCR_OUT2 | UART_MCR_OUT1 |
+		     UART_MCR_DTR | UART_MCR_RTS);
+	up->mcr = old_mcr | mcr;
 	serial_out(up, UART_MCR, up->mcr);
 	pm_runtime_mark_last_busy(up->dev);
 	pm_runtime_put_autosuspend(up->dev);

From 08bd4903c20d9d4bea64b1751386a478faa24ab0 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Fri, 5 Oct 2012 13:54:53 +0100
Subject: [PATCH 10/21] SERIAL: omap: fix MCR TCRTLR bit handling

The MCR TCRTLR bit can only be changed when ECB is set in the EFR.
Unfortunately, several places were trying to alter this bit while ECB
was clear:

- serial_omap_configure_xonxoff() was attempting to clear the bit after
  explicitly clearing the ECB bit.
- serial_omap_set_termios() was trying the same trick after setting the
  SCR, and when trying to change the TCR register when hardware flow
  control was enabled.

Fix this by ensuring that we always have ECB set whenever the TCRTLR bit
is changed.

Moreover, we start out by reading the EFR and MCR registers, which may
have indeterminent bit settings for the ECB and TCRTLR bits.  Ensure
that these bits always start off in a known state.

In order to avoid any undesired behaviour appearing through fixing this,
we also ensure that hardware assisted flow control is disabled while new
driver specific parts are not in place.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 37 ++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index fb06def4d982..170be2b1cdb1 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -706,9 +706,10 @@ serial_omap_configure_xonxoff
 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
-	serial_out(up, UART_EFR, up->efr);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 	serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, up->efr);
 	serial_out(up, UART_LCR, up->lcr);
 }
 
@@ -729,7 +730,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 {
 	struct uart_omap_port *up = to_uart_omap_port(port);
 	unsigned char cval = 0;
-	unsigned char efr = 0;
 	unsigned long flags = 0;
 	unsigned int baud, quot;
 
@@ -839,12 +839,12 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 
-	up->efr = serial_in(up, UART_EFR);
+	up->efr = serial_in(up, UART_EFR) & ~UART_EFR_ECB;
 	up->efr &= ~UART_EFR_SCD;
 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
 
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-	up->mcr = serial_in(up, UART_MCR);
+	up->mcr = serial_in(up, UART_MCR) & ~UART_MCR_TCRTLR;
 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
 	/* FIFO ENABLE, DMA MODE */
 
@@ -863,9 +863,12 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	serial_out(up, UART_OMAP_SCR, up->scr);
 
-	serial_out(up, UART_EFR, up->efr);
+	/* Reset UART_MCR_TCRTLR: this must be done with the EFR_ECB bit set */
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 	serial_out(up, UART_MCR, up->mcr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 
 	/* Protocol, Baud Rate, and Interrupt Settings */
 
@@ -903,21 +906,22 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	/* Hardware Flow Control Configuration */
 
-	if (termios->c_cflag & CRTSCTS) {
-		efr |= (UART_EFR_CTS | UART_EFR_RTS);
+	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
+		/* Enable access to TCR/TLR */
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-
-		up->mcr = serial_in(up, UART_MCR);
 		serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
 
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-		up->efr = serial_in(up, UART_EFR);
-		serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
-
 		serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
-		serial_out(up, UART_EFR, efr); /* Enable AUTORTS and AUTOCTS */
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+
+		/* Enable AUTORTS and AUTOCTS */
+		up->efr |= UART_EFR_CTS | UART_EFR_RTS;
+
+		/* Disable access to TCR/TLR */
 		serial_out(up, UART_MCR, up->mcr | UART_MCR_RTS);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_out(up, UART_EFR, up->efr);
 		serial_out(up, UART_LCR, cval);
 	} else {
 		/* Disable AUTORTS and AUTOCTS */
@@ -930,7 +934,8 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
 	/* Software Flow Control Configuration */
-	serial_omap_configure_xonxoff(up, termios);
+	if (up->port.flags & UPF_SOFT_FLOW)
+		serial_omap_configure_xonxoff(up, termios);
 
 	spin_unlock_irqrestore(&up->port.lock, flags);
 	pm_runtime_mark_last_busy(up->dev);

From 4073a53b36ff993f7c4d158d1cf30d93c7d12add Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Mon, 15 Oct 2012 15:21:46 +0100
Subject: [PATCH 11/21] SERIAL: omap: remove 'irq_pending' bitfield

irq_pending is never used, so let's remove it.  It seems to be  result
of a bad rebase of d37c6cebcb0c (serial: omap: move uart_omap_port
definition to C file)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 170be2b1cdb1..da46be3d57b1 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -99,7 +99,6 @@ struct uart_omap_port {
 	u32			context_loss_cnt;
 	u32			errata;
 	u8			wakeups_enabled;
-	unsigned int		irq_pending:1;
 
 	int			DTR_gpio;
 	int			DTR_inverted;

From f91b55ab72a913a8a61e377a7766772a20f0d96b Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 6 Oct 2012 10:50:58 +0100
Subject: [PATCH 12/21] SERIAL: omap: move driver private definitions and
 structures to driver

struct uart_omap_port and struct uart_omap_dma, and associated
definitions are private to the driver, so there's no point them sitting
in an include file under arch/arm.  Move them into the driver itself.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/plat-omap/include/plat/omap-serial.h | 52 -------------------
 drivers/tty/serial/omap-serial.c              | 52 +++++++++++++++++++
 2 files changed, 52 insertions(+), 52 deletions(-)

diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index 1957a8516e93..8642e9d57b0c 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -30,35 +30,9 @@
  */
 #define OMAP_SERIAL_NAME	"ttyO"
 
-#define OMAP_MODE13X_SPEED	230400
-
-#define OMAP_UART_SCR_TX_EMPTY	0x08
-
-/* WER = 0x7F
- * Enable module level wakeup in WER reg
- */
-#define OMAP_UART_WER_MOD_WKUP	0X7F
-
-/* Enable XON/XOFF flow control on output */
-#define OMAP_UART_SW_TX		0x04
-
-/* Enable XON/XOFF flow control on input */
-#define OMAP_UART_SW_RX		0x04
-
 #define OMAP_UART_SYSC_RESET	0X07
-#define OMAP_UART_TCR_TRIG	0X0F
-#define OMAP_UART_SW_CLR	0XF0
 #define OMAP_UART_FIFO_CLR	0X06
 
-#define OMAP_UART_DMA_CH_FREE	-1
-
-#define OMAP_MAX_HSUART_PORTS	6
-
-#define MSR_SAVE_FLAGS		UART_MSR_ANY_DELTA
-
-#define UART_ERRATA_i202_MDR1_ACCESS	BIT(0)
-#define UART_ERRATA_i291_DMA_FORCEIDLE	BIT(1)
-
 struct omap_uart_port_info {
 	bool			dma_enabled;	/* To specify DMA Mode */
 	unsigned int		uartclk;	/* UART clock rate */
@@ -77,30 +51,4 @@ struct omap_uart_port_info {
 	void (*enable_wakeup)(struct device *, bool);
 };
 
-struct uart_omap_dma {
-	u8			uart_dma_tx;
-	u8			uart_dma_rx;
-	int			rx_dma_channel;
-	int			tx_dma_channel;
-	dma_addr_t		rx_buf_dma_phys;
-	dma_addr_t		tx_buf_dma_phys;
-	unsigned int		uart_base;
-	/*
-	 * Buffer for rx dma.It is not required for tx because the buffer
-	 * comes from port structure.
-	 */
-	unsigned char		*rx_buf;
-	unsigned int		prev_rx_dma_pos;
-	int			tx_buf_size;
-	int			tx_dma_used;
-	int			rx_dma_used;
-	spinlock_t		tx_lock;
-	spinlock_t		rx_lock;
-	/* timer to poll activity on rx dma */
-	struct timer_list	rx_timer;
-	unsigned int		rx_buf_size;
-	unsigned int		rx_poll_rate;
-	unsigned int		rx_timeout;
-};
-
 #endif /* __OMAP_SERIAL_H__ */
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index da46be3d57b1..17babde8febf 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -44,6 +44,8 @@
 
 #include <plat/omap-serial.h>
 
+#define OMAP_MAX_HSUART_PORTS	6
+
 #define UART_BUILD_REVISION(x, y)	(((x) << 8) | (y))
 
 #define OMAP_UART_REV_42 0x0402
@@ -51,10 +53,14 @@
 #define OMAP_UART_REV_52 0x0502
 #define OMAP_UART_REV_63 0x0603
 
+#define UART_ERRATA_i202_MDR1_ACCESS	BIT(0)
+#define UART_ERRATA_i291_DMA_FORCEIDLE	BIT(1)
+
 #define DEFAULT_CLK_SPEED 48000000 /* 48Mhz*/
 
 /* SCR register bitmasks */
 #define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK		(1 << 7)
+#define OMAP_UART_SCR_TX_EMPTY			(1 << 3)
 
 /* FCR register bitmasks */
 #define OMAP_UART_FCR_RX_FIFO_TRIG_MASK			(0x3 << 6)
@@ -71,6 +77,52 @@
 #define OMAP_UART_MVR_MAJ_SHIFT		8
 #define OMAP_UART_MVR_MIN_MASK		0x3f
 
+#define OMAP_UART_DMA_CH_FREE	-1
+
+#define MSR_SAVE_FLAGS		UART_MSR_ANY_DELTA
+#define OMAP_MODE13X_SPEED	230400
+
+/* WER = 0x7F
+ * Enable module level wakeup in WER reg
+ */
+#define OMAP_UART_WER_MOD_WKUP	0X7F
+
+/* Enable XON/XOFF flow control on output */
+#define OMAP_UART_SW_TX		0x4
+
+/* Enable XON/XOFF flow control on input */
+#define OMAP_UART_SW_RX		0x4
+
+#define OMAP_UART_SW_CLR	0xF0
+
+#define OMAP_UART_TCR_TRIG	0x0F
+
+struct uart_omap_dma {
+	u8			uart_dma_tx;
+	u8			uart_dma_rx;
+	int			rx_dma_channel;
+	int			tx_dma_channel;
+	dma_addr_t		rx_buf_dma_phys;
+	dma_addr_t		tx_buf_dma_phys;
+	unsigned int		uart_base;
+	/*
+	 * Buffer for rx dma.It is not required for tx because the buffer
+	 * comes from port structure.
+	 */
+	unsigned char		*rx_buf;
+	unsigned int		prev_rx_dma_pos;
+	int			tx_buf_size;
+	int			tx_dma_used;
+	int			rx_dma_used;
+	spinlock_t		tx_lock;
+	spinlock_t		rx_lock;
+	/* timer to poll activity on rx dma */
+	struct timer_list	rx_timer;
+	unsigned int		rx_buf_size;
+	unsigned int		rx_poll_rate;
+	unsigned int		rx_timeout;
+};
+
 struct uart_omap_port {
 	struct uart_port	port;
 	struct uart_omap_dma	uart_dma;

From fd9980c761d4ea15a51ce2aaf5dd9dddc299519e Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 6 Oct 2012 10:58:27 +0100
Subject: [PATCH 13/21] SERIAL: omap: remove OMAP_UART_SYSC_RESET and
 OMAP_UART_FIFO_CLR

OMAP_UART_SYSC_RESET and OMAP_UART_FIFO_CLR are unused, remove them.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/plat-omap/include/plat/omap-serial.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index 8642e9d57b0c..ff9b0aab5281 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -30,9 +30,6 @@
  */
 #define OMAP_SERIAL_NAME	"ttyO"
 
-#define OMAP_UART_SYSC_RESET	0X07
-#define OMAP_UART_FIFO_CLR	0X06
-
 struct omap_uart_port_info {
 	bool			dma_enabled;	/* To specify DMA Mode */
 	unsigned int		uartclk;	/* UART clock rate */

From 820344fe3de78e9fdc7691cd6076703683f5a6f4 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Fri, 5 Oct 2012 22:26:06 +0100
Subject: [PATCH 14/21] SERIAL: omap: configure xon/xoff before setting modem
 control lines

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 17babde8febf..9f54cef56765 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -983,11 +983,12 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial_out(up, UART_LCR, cval);
 	}
 
-	serial_omap_set_mctrl(&up->port, up->port.mctrl);
 	/* Software Flow Control Configuration */
 	if (up->port.flags & UPF_SOFT_FLOW)
 		serial_omap_configure_xonxoff(up, termios);
 
+	serial_omap_set_mctrl(&up->port, up->port.mctrl);
+
 	spin_unlock_irqrestore(&up->port.lock, flags);
 	pm_runtime_mark_last_busy(up->dev);
 	pm_runtime_put_autosuspend(up->dev);

From 01d70bb37ccb74a1b5c9e3e08c9a69eacc8d84f4 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Mon, 15 Oct 2012 16:50:59 +0100
Subject: [PATCH 15/21] SERIAL: omap: serial_omap_configure_xonxoff() contents
 into set_termios

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 112 +++++++++++++++----------------
 1 file changed, 53 insertions(+), 59 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 9f54cef56765..4888bd1ab322 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -707,63 +707,6 @@ static void serial_omap_shutdown(struct uart_port *port)
 	free_irq(up->port.irq, up);
 }
 
-static inline void
-serial_omap_configure_xonxoff
-		(struct uart_omap_port *up, struct ktermios *termios)
-{
-	up->lcr = serial_in(up, UART_LCR);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	up->efr = serial_in(up, UART_EFR);
-	serial_out(up, UART_EFR, up->efr & ~UART_EFR_ECB);
-
-	serial_out(up, UART_XON1, termios->c_cc[VSTART]);
-	serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
-
-	/* clear SW control mode bits */
-	up->efr &= OMAP_UART_SW_CLR;
-
-	/*
-	 * IXON Flag:
-	 * Enable XON/XOFF flow control on output.
-	 * Transmit XON1, XOFF1
-	 */
-	if (termios->c_iflag & IXON)
-		up->efr |= OMAP_UART_SW_TX;
-
-	/*
-	 * IXOFF Flag:
-	 * Enable XON/XOFF flow control on input.
-	 * Receiver compares XON1, XOFF1.
-	 */
-	if (termios->c_iflag & IXOFF)
-		up->efr |= OMAP_UART_SW_RX;
-
-	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-
-	up->mcr = serial_in(up, UART_MCR);
-
-	/*
-	 * IXANY Flag:
-	 * Enable any character to restart output.
-	 * Operation resumes after receiving any
-	 * character after recognition of the XOFF character
-	 */
-	if (termios->c_iflag & IXANY)
-		up->mcr |= UART_MCR_XONANY;
-	else
-		up->mcr &= ~UART_MCR_XONANY;
-
-	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-	serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	serial_out(up, UART_EFR, up->efr);
-	serial_out(up, UART_LCR, up->lcr);
-}
-
 static void serial_omap_uart_qos_work(struct work_struct *work)
 {
 	struct uart_omap_port *up = container_of(work, struct uart_omap_port,
@@ -984,8 +927,59 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 	}
 
 	/* Software Flow Control Configuration */
-	if (up->port.flags & UPF_SOFT_FLOW)
-		serial_omap_configure_xonxoff(up, termios);
+	if (up->port.flags & UPF_SOFT_FLOW) {
+		up->lcr = serial_in(up, UART_LCR);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		up->efr = serial_in(up, UART_EFR);
+		serial_out(up, UART_EFR, up->efr & ~UART_EFR_ECB);
+
+		serial_out(up, UART_XON1, termios->c_cc[VSTART]);
+		serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
+
+		/* clear SW control mode bits */
+		up->efr &= OMAP_UART_SW_CLR;
+
+		/*
+		 * IXON Flag:
+		 * Enable XON/XOFF flow control on output.
+		 * Transmit XON1, XOFF1
+		 */
+		if (termios->c_iflag & IXON)
+			up->efr |= OMAP_UART_SW_TX;
+
+		/*
+		 * IXOFF Flag:
+		 * Enable XON/XOFF flow control on input.
+		 * Receiver compares XON1, XOFF1.
+		 */
+		if (termios->c_iflag & IXOFF)
+			up->efr |= OMAP_UART_SW_RX;
+
+		serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+
+		up->mcr = serial_in(up, UART_MCR);
+
+		/*
+		 * IXANY Flag:
+		 * Enable any character to restart output.
+		 * Operation resumes after receiving any
+		 * character after recognition of the XOFF character
+		 */
+		if (termios->c_iflag & IXANY)
+			up->mcr |= UART_MCR_XONANY;
+		else
+			up->mcr &= ~UART_MCR_XONANY;
+
+		serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+		serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_out(up, UART_EFR, up->efr);
+		serial_out(up, UART_LCR, up->lcr);
+	}
 
 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
 

From 1fe8aa8803536b8030375525a07a152ba8f15363 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 6 Oct 2012 09:04:03 +0100
Subject: [PATCH 16/21] SERIAL: omap: don't read back LCR/MCR/EFR

There's really no reason to read back these registers while setting
the termios modes, provided we keep our cached copies up to date.
Remove these readbacks.

This has the benefit that we know that the EFR_ECB and MCR_TCRTLR
bits will always be clear, so we don't need to keep masking these
bits throughout the code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 4888bd1ab322..6d588e20c648 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -912,8 +912,11 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		/* Enable AUTORTS and AUTOCTS */
 		up->efr |= UART_EFR_CTS | UART_EFR_RTS;
 
+		/* Ensure MCR RTS is asserted */
+		up->mcr |= UART_MCR_RTS;
+
 		/* Disable access to TCR/TLR */
-		serial_out(up, UART_MCR, up->mcr | UART_MCR_RTS);
+		serial_out(up, UART_MCR, up->mcr);
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 		serial_out(up, UART_EFR, up->efr);
 		serial_out(up, UART_LCR, cval);
@@ -928,10 +931,8 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	/* Software Flow Control Configuration */
 	if (up->port.flags & UPF_SOFT_FLOW) {
-		up->lcr = serial_in(up, UART_LCR);
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-		up->efr = serial_in(up, UART_EFR);
-		serial_out(up, UART_EFR, up->efr & ~UART_EFR_ECB);
+		serial_out(up, UART_EFR, up->efr);
 
 		serial_out(up, UART_XON1, termios->c_cc[VSTART]);
 		serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
@@ -958,8 +959,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 
-		up->mcr = serial_in(up, UART_MCR);
-
 		/*
 		 * IXANY Flag:
 		 * Enable any character to restart output.
@@ -975,7 +974,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 		serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-		serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR);
+		serial_out(up, UART_MCR, up->mcr);
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 		serial_out(up, UART_EFR, up->efr);
 		serial_out(up, UART_LCR, up->lcr);

From 18f360f865cffde44b112577fed1a6a0dd2740dc Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 6 Oct 2012 09:08:20 +0100
Subject: [PATCH 17/21] SERIAL: omap: simplify

We have the sequence:
	- LCR mode B
	- write EFR with ECB clear
	- LCR mode normal
	- if s/w flow
		- LCR mode B
		- write EFR with ECB clear
		...
		- LCR mode B
		- write EFR with ECB clear
		- LCR mode normal

This can be simplified to:
	- if s/w flow
		- LCR mode B
		- write EFR with ECB clear
		...
	- LCR mode B
	- write EFR with ECB clear
	- LCR mode normal

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 6d588e20c648..fbce4c2e55cf 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -917,19 +917,11 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 
 		/* Disable access to TCR/TLR */
 		serial_out(up, UART_MCR, up->mcr);
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-		serial_out(up, UART_EFR, up->efr);
-		serial_out(up, UART_LCR, cval);
 	} else {
 		/* Disable AUTORTS and AUTOCTS */
 		up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS);
-
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-		serial_out(up, UART_EFR, up->efr);
-		serial_out(up, UART_LCR, cval);
 	}
 
-	/* Software Flow Control Configuration */
 	if (up->port.flags & UPF_SOFT_FLOW) {
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 		serial_out(up, UART_EFR, up->efr);
@@ -975,11 +967,12 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 		serial_out(up, UART_MCR, up->mcr);
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-		serial_out(up, UART_EFR, up->efr);
-		serial_out(up, UART_LCR, up->lcr);
 	}
 
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, up->lcr);
+
 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
 
 	spin_unlock_irqrestore(&up->port.lock, flags);

From c7d059cae31f328bbe2be6ab737226d338f22486 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 6 Oct 2012 09:12:44 +0100
Subject: [PATCH 18/21] SERIAL: omap: always set TCR

We always setup the TCR register in the software flow control path,
and when hardware flow control is enabled.  Remove this redundant
setup, and place it before we setup any hardware flow control.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index fbce4c2e55cf..7180ffc847e8 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -898,31 +898,30 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 	else
 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
 
+	/* Enable access to TCR/TLR */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
+
+	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
+
 	/* Hardware Flow Control Configuration */
 
 	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
-		/* Enable access to TCR/TLR */
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-		serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-		serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
-
-		serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
-
 		/* Enable AUTORTS and AUTOCTS */
 		up->efr |= UART_EFR_CTS | UART_EFR_RTS;
 
 		/* Ensure MCR RTS is asserted */
 		up->mcr |= UART_MCR_RTS;
-
-		/* Disable access to TCR/TLR */
-		serial_out(up, UART_MCR, up->mcr);
 	} else {
 		/* Disable AUTORTS and AUTOCTS */
 		up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS);
 	}
 
 	if (up->port.flags & UPF_SOFT_FLOW) {
+		/* Disable access to TCR/TLR */
+		serial_out(up, UART_MCR, up->mcr);
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 		serial_out(up, UART_EFR, up->efr);
 
@@ -961,14 +960,9 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 			up->mcr |= UART_MCR_XONANY;
 		else
 			up->mcr &= ~UART_MCR_XONANY;
-
-		serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-		serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-		serial_out(up, UART_MCR, up->mcr);
 	}
 
+	serial_out(up, UART_MCR, up->mcr);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 	serial_out(up, UART_EFR, up->efr);
 	serial_out(up, UART_LCR, up->lcr);

From c533e51b228020142cd2c4d5f21e8db4683ce457 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 6 Oct 2012 09:34:36 +0100
Subject: [PATCH 19/21] SERIAL: omap: move xon/xoff setting earlier

Take advantage of the switch to mode B for accessing the TCR register,
and move the xon/xoff configuration there.  This allows further
simplication of this sequence.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 7180ffc847e8..0d2671e66da4 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -898,16 +898,20 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 	else
 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
 
-	/* Enable access to TCR/TLR */
+	/* Configure flow control */
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+	/* XON1/XOFF1 accessible mode B, TCRTLR=0, ECB=0 */
+	serial_out(up, UART_XON1, termios->c_cc[VSTART]);
+	serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
+
+	/* Enable access to TCR/TLR */
 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
 
 	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
 
-	/* Hardware Flow Control Configuration */
-
 	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
 		/* Enable AUTORTS and AUTOCTS */
 		up->efr |= UART_EFR_CTS | UART_EFR_RTS;
@@ -925,9 +929,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 		serial_out(up, UART_EFR, up->efr);
 
-		serial_out(up, UART_XON1, termios->c_cc[VSTART]);
-		serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
-
 		/* clear SW control mode bits */
 		up->efr &= OMAP_UART_SW_CLR;
 

From 2405464083e152f88bb58b7108a9e50ca362178c Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 6 Oct 2012 09:36:47 +0100
Subject: [PATCH 20/21] SERIAL: omap: simplify (2)

Simplify:
	- set ECB
	...
	- LCR mode A
	- clear TCRTLR
	- LCR mode B
	- clear ECB
	- set ECB and update other bits
	- LCR mode A
	- update XONANY

to:
	- set ECB
	...
	- LCR mode B
	- set ECB and update other bits
	- LCR mode A
	- update XONANY and clear TCRTLR

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 0d2671e66da4..156a85438558 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -924,11 +924,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 	}
 
 	if (up->port.flags & UPF_SOFT_FLOW) {
-		/* Disable access to TCR/TLR */
-		serial_out(up, UART_MCR, up->mcr);
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-		serial_out(up, UART_EFR, up->efr);
-
 		/* clear SW control mode bits */
 		up->efr &= OMAP_UART_SW_CLR;
 
@@ -948,9 +943,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		if (termios->c_iflag & IXOFF)
 			up->efr |= OMAP_UART_SW_RX;
 
-		serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-
 		/*
 		 * IXANY Flag:
 		 * Enable any character to restart output.
@@ -962,7 +954,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 		else
 			up->mcr &= ~UART_MCR_XONANY;
 	}
-
 	serial_out(up, UART_MCR, up->mcr);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 	serial_out(up, UART_EFR, up->efr);

From 3af08bd7adb09b0806c51c06b87db08cc7075568 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Fri, 5 Oct 2012 13:32:08 +0100
Subject: [PATCH 21/21] SERIAL: omap: fix hardware assisted flow control

When the UART device has hardware flow control enabled, it ignores the
MCR RTS bit in the MCR register, and keeps RTS asserted as long as we
continue to read characters from the UART receiver FIFO.  This means
that when the TTY buffers become full, the UART doesn't tell the remote
end to stop sending, which causes the TTY layer to start dropping
characters.

A similar problem exists with software flow control.  We need the FIFO
register to fill when software flow control is enabled to provoke the
UART to send the XOFF character.

Fix this by implementing the throttle/unthrottle callbacks, and use
these to disable receiver interrupts.  This in turn means that the UART
FIFO will fill, which will then cause the UART's hardware to deassert
the RTS signal and/or send the XOFF character, stopping the remote end.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/tty/serial/omap-serial.c | 53 +++++++++++++++++++++++++-------
 1 file changed, 42 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 156a85438558..4dbbc00c8266 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -88,10 +88,10 @@
 #define OMAP_UART_WER_MOD_WKUP	0X7F
 
 /* Enable XON/XOFF flow control on output */
-#define OMAP_UART_SW_TX		0x4
+#define OMAP_UART_SW_TX		0x08
 
 /* Enable XON/XOFF flow control on input */
-#define OMAP_UART_SW_RX		0x4
+#define OMAP_UART_SW_RX		0x02
 
 #define OMAP_UART_SW_CLR	0xF0
 
@@ -354,6 +354,34 @@ static void serial_omap_start_tx(struct uart_port *port)
 	pm_runtime_put_autosuspend(up->dev);
 }
 
+static void serial_omap_throttle(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned long flags;
+
+	pm_runtime_get_sync(up->dev);
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+	serial_out(up, UART_IER, up->ier);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	pm_runtime_mark_last_busy(up->dev);
+	pm_runtime_put_autosuspend(up->dev);
+}
+
+static void serial_omap_unthrottle(struct uart_port *port)
+{
+	struct uart_omap_port *up = to_uart_omap_port(port);
+	unsigned long flags;
+
+	pm_runtime_get_sync(up->dev);
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->ier |= UART_IER_RLSI | UART_IER_RDI;
+	serial_out(up, UART_IER, up->ier);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	pm_runtime_mark_last_busy(up->dev);
+	pm_runtime_put_autosuspend(up->dev);
+}
+
 static unsigned int check_modem_status(struct uart_omap_port *up)
 {
 	unsigned int status;
@@ -929,20 +957,20 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 
 		/*
 		 * IXON Flag:
-		 * Enable XON/XOFF flow control on output.
-		 * Transmit XON1, XOFF1
-		 */
-		if (termios->c_iflag & IXON)
-			up->efr |= OMAP_UART_SW_TX;
-
-		/*
-		 * IXOFF Flag:
 		 * Enable XON/XOFF flow control on input.
 		 * Receiver compares XON1, XOFF1.
 		 */
-		if (termios->c_iflag & IXOFF)
+		if (termios->c_iflag & IXON)
 			up->efr |= OMAP_UART_SW_RX;
 
+		/*
+		 * IXOFF Flag:
+		 * Enable XON/XOFF flow control on output.
+		 * Transmit XON1, XOFF1
+		 */
+		if (termios->c_iflag & IXOFF)
+			up->efr |= OMAP_UART_SW_TX;
+
 		/*
 		 * IXANY Flag:
 		 * Enable any character to restart output.
@@ -1025,6 +1053,7 @@ static void serial_omap_config_port(struct uart_port *port, int flags)
 	dev_dbg(up->port.dev, "serial_omap_config_port+%d\n",
 							up->port.line);
 	up->port.type = PORT_OMAP;
+	up->port.flags |= UPF_SOFT_FLOW | UPF_HARD_FLOW;
 }
 
 static int
@@ -1228,6 +1257,8 @@ static struct uart_ops serial_omap_pops = {
 	.get_mctrl	= serial_omap_get_mctrl,
 	.stop_tx	= serial_omap_stop_tx,
 	.start_tx	= serial_omap_start_tx,
+	.throttle	= serial_omap_throttle,
+	.unthrottle	= serial_omap_unthrottle,
 	.stop_rx	= serial_omap_stop_rx,
 	.enable_ms	= serial_omap_enable_ms,
 	.break_ctl	= serial_omap_break_ctl,